EP3445528B1 - Device and method for inserting a tool into a tool holder - Google Patents

Description

The present invention relates to a device and a method for inserting a tool into a tool holder and is particularly, but not exclusively, directed to shrinking devices which shrink a rotary tool into or out of the central receiving opening of a tool holder. The invention is also suitable, for example, for tool holders with elastically deformable clamping elements, for example polygonal or cylindrical clamping sections, or also for tool holders with clamp clamping.

For machine tools that work with high speeds or special precision requirements, in particular drilling, milling or lathes, the use of shrink fit chucks is widespread, as they work with particularly high concentricity and particularly reliable torque transmission between tool holder and tool. Such tool holders have a central receiving opening whose diameter is slightly smaller than the outer diameter of the tool to be held. To insert the tool into the tool holder, the latter is heated, for example using an inductive heating device or a fan heater, until the holder opening has widened sufficiently to be able to insert the tool. When the tool holder cools down, possibly supported by a cooling device, the tool holder shrinks and reliably clamps the tool on all sides. To remove the tool, the tool holder is heated again until the tool can be pulled out of the holder opening.

One from the EP 1 310 323 A2 known shrinking device of the type mentioned above comprises a first holding device for holding the tool holder and a second holding device for holding the tool, wherein the second holding device can be approached with the tool via a threaded spindle to the first holding device, so that the tool penetrates into the tool holder. An optical detection arrangement can be moved in the axial direction along the device and allows a cutting edge of the tool to be detected in a crosshair. The axial position of the detection arrangement is measured by a measuring arrangement and fed to an electronic control device, which controls the axial movement of the second holding device by an electric motor, so that the tool can be clamped in a desired axial position in the tool holder.

The ones from the EP 1 310 323 A2 known device is designed for a fully automatic shrinking and shrinking process and accordingly has a relatively complicated structure and a large number of moving parts. For example, the first holding device is also designed in the form of an axially displaceable carriage. The precision of the axial positioning of the tool and tool holder is therefore limited by play and wear of individual moving components and it is necessary to check the overall length of the tool and tool holder assembly after shrinking and, if there is any deviation, correct the positioning by unshrinking and re-shrinking to shrink down.

DE 10 2005 003927 discloses a device according to the preamble of claim 1.

Further problems of known devices arise when handling very small tools, ie for example rotary tools with a diameter of less than 10 mm. Such tools are heavily stressed, for example, by using conventional shrinking processes, and are regularly damaged. For micro tools with a cutting edge diameter of less than 1 mm to less than 0.1 mm, they break Cut off at the lightest touch. For tools of this type, the prior art generally lacks suitable devices and methods for inserting such tools into a corresponding tool holder.

Against this background, the object of the present invention is to provide a device for inserting a tool into a tool holder which, with a simple design, allows very precise axial positioning of the tool in the tool holder and which is also suitable for handling sensitive tools, particularly very small tools , suitable is. Furthermore, it is the object of the present invention to provide a method for inserting a tool into a tool holder, which enables the precise axial positioning of the tool in the tool holder with acceptable operating effort and costs and, if necessary, also allows the handling of small and sensitive tools.

According to a first aspect of the invention, the stated object is achieved by a device for inserting a tool into a tool holder, comprising a first holding device, which is set up to hold a tool holder, a second holding device, which is set up to hold a tool , a linear guide by means of which the second holding device can be moved relative to the first holding device in an axial direction running along or parallel to a main axis (X) in order to approach the tool to the tool holder and to introduce it into the tool holder, a detection arrangement which can be moved in the axial direction and which is set up to detect an axial position of a first reference point assigned to the first holding device without contact and to detect an axial position of a second reference point of a tool held by the second holding device without contact, and a measuring arrangement which measures an axial displacement path of the Detection arrangement measures, wherein the detection arrangement is connected to the second holding device and moves together with this in the axial direction on the linear guide.

In a device according to the invention of the first aspect, contactless detection of at least two reference points takes place, namely on the tool and on the tool holder, so that the tool can be positioned axially relative to the tool holder on the basis of both reference points. In contrast to conventional devices, not only is the axial position of the tool precisely detected, but the device according to the invention is also set up to precisely detect an additional reference point on the first holding device that carries the tool holder. In this way, the actual total length of the tool assembly to be produced, consisting of tool and tool holder, can be scanned during each measuring process, so that any inaccuracies in the frame or in other parts of the device due to wear or play do not affect the precision of the relative axial positioning of the tool and tool holder.

According to a further feature of the invention of the first aspect, the detection arrangement is connected to the second holding device and moves together with it in the axial direction on the linear guide. The consequence of this is that the measuring arrangement, which measures the axial displacement path of the detection arrangement, can simultaneously provide information about the actual axial displacement of the tool relative to the tool holder.

An optical detection arrangement can be used for the contactless detection of the first and the second reference point, for example a camera and an image processing device connected to it with a display device. Alternatively is one contactless detection using transmitted light or ultrasonic waves is possible. The contactless detection avoids mechanical stress on the tool and thus allows the handling of small or sensitive tools without the risk of damage. An area of a cutting edge, e.g. B. in the axial direction foremost (facing away from the tool holder) cutting edge, selected as the second reference point, since this is also the corresponding reference point for determining an overall length of the tool assembly of tool and tool holder. Due to the contactless detection, the reference point can be determined very precisely without touching and thus damaging the cutting edge.

The second holding device configured to hold the tool can preferably comprise a base section mounted so as to be axially movable on the linear guide and a carriage mounted so as to be axially movable on the base section, the carriage having holding means for holding a tool. By adjusting the axial position of the carriage, an exact position of the tool held on the carriage can be adjusted relative to the base section of the second holding device and the tool can be positioned relative to the detection arrangement. If, in particular, the detection arrangement is connected to the base section, the axial position of the tool can be adjusted by displacing the carriage in such a way that the detection arrangement just detects the second reference point of the tool. For example, the detection arrangement can have a target area, such as a crosshair or the like, which is superimposed on a detected image of the tool, and an operator can then adjust the carriage in the axial direction in such a way that a cutting edge recognizable in the image or another reference point of the tool just in the target area.

Used to adjust the axial position of the carriage relative to the base section For example, a threaded spindle with a handle portion that can be rotated manually by the operator, a linear guide driven by an electric motor, or the like can be used.

In a further preferred embodiment of the invention, the device has a stop which can be displaced in the axial direction and fixed in different axial positions, the stop being set up to limit an axial movement of the second holding device along the linear guide. The stop allows a specific axial position of the second holding device to be marked and precisely approached again. In this way, for example, an axial displacement path can be measured according to a desired overall length of the tool assembly made up of tool and tool holder by moving the detection arrangement from the first reference point to the corresponding displacement path and fixing the stop at this point. A tool can then be inserted into the second holding device and after the tool holder has been opened, the second holding device can be moved with the tool until it reaches the stop on the first holding device in order to insert the tool into the desired axial position in the tool holder.

In a further embodiment of the present invention, it is provided that the first holding device comprises: a frame element, a clamping device which can be mounted on the frame element and which has first coupling means for coupling a tool holder, and a calibration body which can be mounted on the frame element instead of the clamping device, the first reference point is provided on a contactlessly detectable edge or surface of the calibration body. The clamping device can be part of a machine tool at the same time, in which the finished tool assembly consisting of tool holder and tool is finally to be clamped in order to achieve the desired machining Workpiece to make by the tool. The machine tool could be a drill or a lathe, for example. The frame element of the first holding device can include such a clamping device as a replacement part or can be used with a clamping device specially adapted for the device according to the invention, which has corresponding coupling means for coupling the tool holder. According to the embodiment of the invention described above, instead of the clamping device, a calibration body can also be mounted on the frame element for a calibration process, which is constructed in such a way that a predetermined first reference point of the calibration body (e.g. a front edge or surface of the calibration body) exactly the axial Position of a predetermined reference point of the fixture (e.g. a leading edge or surface). The advantage of using a calibration body instead of the clamping device itself is that the shape of the calibration body in the area of the reference point can be specially designed for very precise detection of this reference point and, for this purpose, can have a particularly precisely designed edge or surface that is the contactless recording method can be recorded well.

The axial length of the calibration body can be equal to the axial length of the clamping device and the first reference point can be provided on an end of the calibration body facing away from the frame element and can be formed, for example, by an edge or curve. In particular when using an optical measurement by a camera or the like, this allows a very precise detection of the reference point, since a front edge or rounding can be well focused and distinguished from the background.

Furthermore, the tool can be a rotary tool and the tool holder can be a tool chuck for accommodating the rotary tool. For rotary tools, the precision of the axial position of the tool relative to the tool holder plays a particularly important role and there is an increasing need to use particularly small tools and micro-tools. In particular, it is considered that the device of the invention of the first or second aspect is a shrinking device and for this purpose preferably also comprises a heating device for heating a tool holder held on the first holding device. Depending on the embodiment, the device can also include a cooling device for cooling the tool holder in order to accelerate the shrinking process.

The cooling device for cooling the tool holder can advantageously be integrated into the housing of the heating device in order to reduce the operating effort when converting the device between heating and cooling the tool holder. In particular, the cooling device can be set up to cool the tool holder held on the first holding device after it has been heated by spraying on CO ₂ . It was found that a particularly high cooling effectiveness can be achieved by means of CO ₂ . For particularly uniform cooling of the tool holder, the cooling device can preferably have three or more outlet openings for CO ₂ directed toward the tool holder.

In an advantageous variant of the invention of the first aspect, it is further provided that the second holding device comprises: a base section which is mounted in an axially movable manner on the linear guide, an extension section which is mounted in an axially movable manner in relation to the base section and which is preferably a component of the detection arrangement, for example an illumination device, and a cantilever spring assembly axially biasing the cantilever portion toward the base portion and the first retainer, the base portion having a stop limiting axial movement of the cantilever portion. Such a construction has the effect that part of the second Holding device, for example the lighting device of the detection arrangement, is held in the exact position on the base section by the cantilever spring arrangement and when the second holding device approaches the first holding device it is moved with the base section, but that when the two holding devices approach each other more closely during the insertion of the tool into the Tool holder, the cantilever section can strike against a part of the device associated with the first holding device (for example on a heating device attached to the tool holder) and consequently can lift off the stop of the base section. The base section, and thus also the tool, can then move further in the direction of the first holding device until the tool is fully inserted into the tool holder, while the cantilever section remains.

Since the cantilever section lifts off the stop of the base section against the force of the cantilever spring arrangement when the second holding device approaches the first holding device closely, the cantilever spring arrangement can simultaneously assume an advantageous function when the tool is removed from the tool holder: the force of the cantilever spring arrangement then acts between the tool and tool holder. As soon as the tool holder opens (for example after the tool holder has been heated in the case of a shrink device), the cantilever spring arrangement automatically pulls the tool out of the tool holder.

1. a. Bereitstellen von Werkzeugaufnahme und Werkzeug in einem axialen Abstand voneinander,
2. b. kontaktloses Erfassen der axialen Position eines der Werkzeugaufnahme zugeordneten ersten Referenzpunkts,
3. c. kontaktloses Erfassen der axialen Position eines dem Werkzeug zugeordneten zweiten Referenzpunkts,
4. d. Öffnen der Werkzeugaufnahme,
5. e. Einführen des Werkzeugs in die Werkzeugaufnahme, so dass ein Abstand zwischen dem ersten Referenzpunkt und dem zweiten Referenzpunkt einen vorbestimmten Sollwert annimmt,
6. f. Schließen der Werkzeugaufnahme.

According to a further aspect of the present invention, the above-mentioned object of the invention is achieved by a method for inserting a tool into a tool holder, comprising the steps

1. a. Provision of tool holder and tool at an axial distance from each other,
2. b. contactless detection of the axial position of one of the tool holder associated first reference point,
3. c. contactless detection of the axial position of a second reference point assigned to the tool,
4. i.e. opening the tool holder,
5. e. Inserting the tool into the tool holder so that a distance between the first reference point and the second reference point assumes a predetermined target value,
6. f. Closing the tool holder.

With a method of the further aspect of the invention, the effects and advantages described in connection with the first aspect are achieved in particular, which are based on not only detecting the axial position of the tool but also determining two reference points without contact, a first reference point assigned to the tool holder and a second reference point associated with the tool. According to an important feature of the method of the invention of the further aspect, the axial positioning between the tool and the tool holder then takes place on the basis of a distance between the first reference point and the second reference point. In particular, the tool is inserted into the tool holder until the distance between the reference points assumes a predetermined desired value. Only then is the tool holder closed.

In other words, with the method of the further aspect of the invention as well as with the device of the first aspect of the invention, an overall length of a tool assembly consisting of tool holder and tool can already be measured before the tool holder is closed. Both of the reference points that are decisive for measuring this length are precisely recorded during each shrinking process, so that inaccuracies in the position of other parts of the device due to play, wear or the like do not affect precision.

1. a. kontaktloses Erfassen der axialen Position des ersten Referenzpunkts,
2. b. axiales Bewegen der Erfassungseinrichtung an diejenige Position, an der sich die Erfassungseinrichtung in einem gewünschten Abstand vom ersten Referenzpunkt befindet;
3. c. Einstellen einer Positioniereinrichtung entsprechend der axialen Position der Erfassungseinrichtung,
4. d. Einsetzen des Werkzeugs in die zweite Halteeinrichtung,
5. e. kontaktloses Erfassen der axialen Position des zweiten Referenzpunkts des von der zweiten Halteeinrichtung gehaltenen Werkzeugs,
6. f. Öffnen der Werkzeugaufnahme,
7. g. Annähern der zweiten Halteeinrichtung und der ersten Halteeinrichtung aneinander, so dass das Werkzeug in die Werkzeugaufnahme eindringt,
8. h. Stopp der Annäherungsbewegung durch die Positioniereinrichtung,
9. i. Schließen der Werkzeugaufnahme,
10. j. Lösen des Werkzeugs von der zweiten Halteeinrichtung.

In a preferred embodiment of the method according to the further aspect of the invention, it is proposed that a device is used which comprises: a first holding device, which is set up to hold a tool holder, a second holding device, which is set up to hold a tool hold, a linear guide, by means of which the second holding device can be moved axially relative to the first holding device, in order to bring the tool closer to the tool holder and to introduce it into the tool holder, a detection arrangement which can be moved axially and which is set up to determine an axial position of one of the first holding devices to detect an associated first reference point without contact and to detect an axial position of a second reference point of a tool held by the second holding device without contact, and a measuring arrangement which measures an axial displacement path of the detection arrangement, the method comprising the following steps:

1. a. contactless detection of the axial position of the first reference point,
2. b. axially moving the detector to the position where the detector is a desired distance from the first reference point;
3. c. adjusting a positioning device according to the axial position of the detection device,
4. i.e. inserting the tool into the second holding device,
5. e. contactless detection of the axial position of the second reference point of the tool held by the second holding device,
6. f. opening the tool holder,
7. G. Approaching the second holding device and the first holding device to each other so that the tool penetrates into the tool holder,
8. H. stop the approach movement by the positioning device,
9. i. closing the tool holder,
10. j. Detaching the tool from the second holding device.

The above method allows the first and second reference points to be detected and marked with simple work steps and a tool to be quickly inserted into a tool holder with reliable and precise axial positioning of both components for producing a tool assembly with a predetermined desired length. In the case of shrinkage clamping in particular, the time window for inserting the tool after heating and thus widening the clamping bore is relatively short, so that rapid introduction of the tool into the clamping bore is advantageous.

Even if the present invention is preferably intended to facilitate manual insertion of a tool into a tool holder, the device described is also suitable for integration into fully automated processes. It is relatively easy to set up independent transfer positions from or to external devices, such as a robot's gripper arm, since the exact tool position is recorded anew with each clamping process. A high-precision and thus technically complex tool transfer is not required. A possible embodiment of such a fully automated process is, for example, in DE 202015006540 U1 described.

Correspondingly, the entire method for inserting a tool into a tool holder can run in a process-controlled manner, so that all the steps described run automatically.

The preferred use of an optical detection arrangement also enables the tool to be displayed on a monitor. The image from the camera can also be displayed enlarged on a monitor, so that the operator can use the camera image to tool used can examine for damage that would not be visible to the naked eye.

Provision can also be made for the tool holder to be able to perform rotational movements in the clamping device. This allows the tool holder to be rotated in the clamping device. If the detection arrangement is positioned accordingly, the clamped tool can thus be viewed from all sides and, if necessary, measured.

Figur 1:

eine perspektivische Ansicht einer Vorrichtung zum Einsetzen eines Werkzeugs in eine Werkzeugaufnahme gemäß einem ersten Ausführungsbeispiel der vorliegenden Erfindung,

Figur 2a:

eine Draufsicht von oben auf die Vorrichtung des ersten Ausführungsbeispiels,

Figur 2b:

eine perspektivische Ansicht eines Kalibrierkörpers der Vorrichtung des ersten Ausführungsbeispiels,

Figur 3:

eine perspektivische Ansicht einer zweiten Halteeinrichtung der Vorrichtung des ersten Ausführungsbeispiels,

Figur 4:

eine Draufsicht von oben auf die zweite Halteeinrichtung des ersten Ausführungsbeispiels,

Figur 5a:

eine axiale Ansicht der zweiten Halteeinrichtung des ersten Ausführungsbeispiels, betrachtet in einer Blickrichtung von der ersten Halteeinrichtung zur zweiten Halteeinrichtung,

Figur 5b:

eine Vergrößerung eines Ausschnitts aus Figur 5a im Bereich zweier Eingriffselemente,

Figur 6:

eine perspektivische Ansicht eines an der zweiten Halteeinrichtung getragenen Schlittens gemäß dem ersten Ausführungsbeispiel der Erfindung,

Figuren 7a bis 7e:

Ansichten in axialer Richtung, von oben, von links, von unten bzw. von rechts, die den Schlitten der zweiten Halteeinrichtung zeigen,

Figur 8:

eine Draufsicht einer Vorrichtung gemäß einem zweiten Ausführungsbeispiel der Erfindung.

The invention is explained in more detail below using preferred exemplary embodiments with reference to the accompanying drawings. Show it:

Figure 1:

a perspective view of a device for inserting a tool into a tool holder according to a first embodiment of the present invention,

Figure 2a:

a top view of the device of the first embodiment,

Figure 2b:

a perspective view of a calibration body of the device of the first embodiment,

Figure 3:

a perspective view of a second holding device of the device of the first embodiment,

Figure 4:

a plan view from above of the second holding device of the first exemplary embodiment,

Figure 5a:

an axial view of the second holding device of the first embodiment, viewed in a viewing direction from the first holding device to the second holding device,

Figure 5b:

an enlargement of a section Figure 5a in the area of two engagement elements,

Figure 6:

a perspective view of a carriage carried on the second holding device according to the first exemplary embodiment of the invention,

Figures 7a to 7e:

Views in the axial direction, from above, from the left, from below and from the right, showing the carriage of the second holding device,

Figure 8:

a plan view of a device according to a second embodiment of the invention.

In figures 1 and 2 a device for inserting a tool into a tool holder according to the first exemplary embodiment of the present invention is generally designated 10 and comprises a first holding device 12, into which a tool holder 14 is inserted, and a second holding device 16, which holds a tool 18. A main axis X of the device 10 runs through the centers of the tool holder 14 and the tool 18. In the exemplary embodiment described here, the device 10 is a shrinking device for thermally shrinking a rotary tool, for example a drill, into and out of a tool holder, the receiving opening of which expands as a result of heating expands to accommodate or release the tool. However, the principles of the present invention can also be transferred to tool holders that can be adjusted, for example, by applying compressive force or by a thread mechanism or in some other way.

The device 10 further includes a linear guide 20, through which the second holding device 16 is movable relative to the first holding device along or parallel to the main axis X. Directions that run along or parallel to the main axis X are referred to as axial directions in the context of this disclosure. The linear guide 20 can be implemented, for example, by a rail 22 on which a base section 24 of the second holding device 16 is mounted in a linearly displaceable manner. A preferably electronically working measuring arrangement detects the axial position of the second holding device 16 along the linear guide 20, for example by inductive scanning, and shows a measured axial displacement path or a measured axial position to the user on a display of a control panel 25 of the measuring arrangement.

The main axis X runs horizontally in the exemplary embodiments. It goes without saying that the course can also be inclined or even vertical.

The movement of the second holding device 16 in the axial direction can be limited by a stop 26, which can be positioned and fixed at various positions in the axial direction. The stop 26 can in particular also be guided in a displaceable manner on the rail 22 of the linear guide 20 and have a locking screw 28 for fixing its axial position.

The first holding device 12 preferably comprises a frame element 30 which is firmly connected to a base body 32, for example a housing, a table or some other frame construction of the device 10. Furthermore, the first holding device preferably has a clamping device 34 which is mounted on the frame element 30 and which corresponds to a clamping device as is present in the corresponding machine tool for which the device 10 prepares the tool and the tool holder. At an axial end facing away from the frame element 30, the clamping device 34 has coupling means for coupling the tool holder 14, for example corresponding ones thread means. A contact surface 36 of the clamping device 34 on a side facing away from the frame element 30 is set up to come into contact with a radial contact surface 38 of the tool holder 14 when the tool holder 14 is correctly coupled to the clamping device 34 . The axial position of the contact surface 36 of the clamping device 34 is therefore equal to the axial position of the radial contact surface 38 of the tool holder 14, so that the axial position of the contact surface 36 of the clamping device 34 is a suitable reference value for the exact determination of the relative position between the tool holder 14 and the tool 18 . The contact surfaces 36, 38 (more precisely, their axial position along the main axis X) define the first reference point R1 within the meaning of the invention.

The device 10 also includes a detection arrangement 40 for the contactless detection of reference points of the holding devices or the tool or the tool holder. The detection arrangement 40 can have a camera 42 which is aligned with the main axis X towards. On a side diametrically opposite the camera 42 with respect to the main axis X, there is an illumination device 44 which illuminates the object to be recorded. In this way, for example, a front edge or cutting edge of a tool creates a sharply defined silhouette that can be precisely captured in the camera image (transmitted light method). The image of the camera 42 is preferably displayed enlarged on a monitor, also not shown, so that the operator can see the camera image when setting and adjusting the device. Alternatively, other contactless detection devices are conceivable, for example an optical projector.

The detection device 40 is connected to the second holding device 16 for joint movement. Thus, in the exemplary embodiment, an arm 46 holding the camera 42 at a radial distance from the main axis X can be connected to the base section 24 of the second holding device 16 or be formed in one piece. Also connected to the base portion 24 in the illustrated embodiment is a second arm 48 which supports the illuminator 44 spaced from the major axis X and diametrically opposed to the camera 42 .

With additional reference to the Figures 3 to 5 further features of the second holding device 16 are described in more detail below. In the exemplary embodiment, a carriage 50 is carried on the base section 24 of the second holding device 16 and can be displaced in the axial direction relative to the base section 24 by a linear guide 52, realized for example by axially running rails 54 and suitable grooves. An adjustment device 56 may also be provided to move the carriage axially and to allow the axial position of the carriage 50 relative to the base portion 24 to be adjusted by an operator. In the illustrated embodiment, a threaded spindle 58 is provided for this purpose, which is rotatably and axially non-displaceably mounted on a bearing element 60 of the base part and which engages in a matching axial internal thread 62 of the carriage 50 . The carriage 50 can then be moved in the axial direction by manual rotation of an adjusting wheel 64 of the threaded spindle 58 (alternatively by means of an electromotive actuator).

Holding means 66 for holding a tool 18 (only in figures 1 and 2 shown) mounted, wherein an advantageous embodiment of the holding means 66 is described in more detail below. By axial displacement of the carriage 50, the holding means 66 and thus also the tool 18 held thereon are moved in the axial direction relative to the base section 24 and thus also relative to the detection arrangement 40, so that the tool 18 can be brought into a predetermined target position which is Detection arrangement 40 can be precisely detected. The detection arrangement can have a target area, for example a crosshair or some other marking in the camera image. A suitable reference point R2, for example a front cutting edge a cutting tool or the like, which is optically recognizable in the camera image, can then be brought exactly into line with the target area in the axial direction. If the tool 18 is correctly positioned in relation to the detection arrangement 40 as a result of the displacement of the carriage 50, then the detection arrangement 40 detects the second reference point R2 in the sense of the present invention.

A preferred variant of the holding means 66 according to the illustrated embodiment is described below with reference to FIG Figures 3 to 6 described in more detail. In this variant, the holding means 66 comprise a clamping arrangement 70 with a control body 72 mounted on the carriage 50 and two engagement elements 741 and 74r movably held on the control body. At their free ends facing away from the control body 72, the engagement elements 74l, 74r have clamping sections 76l, 76r, which are each formed by an axially running, preferably V-shaped groove. The groove openings of the clamping sections 76l, 76r face each other, so that together they form a receptacle for a tool 18, in particular a cylindrical one. An overall axial length of both clamping sections 76l, 76r is preferably less than about 20 mm, preferably less than about 10 mm, so that a rotary tool can be gripped in the area of its shank so as not to touch the sensitive cutting edges of the tool, while at the same time having a sufficient shank length remains clear of the clamping portions to allow a sufficiently wide insertion of the tool into the tool holder 14.

The engaging elements 74l, 74r are movably held on the control body 72 in such a way that they uniformly move toward or away from each other while the clamping portions 76l, 76r are diametrically approached to the main axis X with respect to the main axis X or move away from it . Thus, the tool 18 can be clamped with the correct axis orientation. The engagement elements 74l, 74r can be adjusted by a pneumatic drive, which is integrated in the control body 72. The opening or closing process of the engagement elements 74l, 74r can then be controlled by compressed air supply lines or discharge lines, not shown in the drawings.

According to a further preferred feature of the invention, the clamping arrangement 70 and in particular the control body 72 is not rigidly mounted on the carriage 50, but is resiliently supported via a spring arrangement 80 on the carriage 50 in such a way that the clamping arrangement 70 and thus also the tool held on the holding means 66 18 can move resiliently in at least one direction orthogonal to the main direction X. For this purpose, the carriage 50 has a first carrier element 82-1, which is held resiliently on the carriage 50 via a first spring part 84-1 such that the first carrier element 82-1 can move resiliently in a first radial direction Y1 relative to the carriage 50 . In addition, the carriage 50 can have a second carrier element 82-2, which is resiliently mounted on the carriage 50 via a second spring part 84-2 in such a way that it is resilient along a second radial direction Y2, which preferably runs orthogonally to the first spring direction Y1 relative to the carriage 50 can move. The spring parts 84-1 and 84-2 can each be formed by leaf springs, in particular steel tongues. Preferably, parallelogram guides are used for each spring part 84-1, 84-2, each of which is formed from two leaf springs, in particular thin-walled steel tongues.

The control body 72 of the clamping arrangement 70 or another assembly element of the holding means 66 is fastened to the first carrier element 82-1 or the second carrier element 82-2 using suitable assembly means, for example screw holes. As a result, the clamping arrangement 70 or holding means 66 are resiliently mounted orthogonally to the axial direction in accordance with the spring travel and spring directions Y1, Y2. By choosing appropriate spring elements, for example leaf springs, it is also possible to largely limit a spring movement in the axial direction , so that the precision of the detection of the second reference point R2 by the detection arrangement 40 is not impaired.

A method for inserting a tool 18 into a tool holder 14 according to an exemplary embodiment of the invention is explained in more detail below with reference to the drawings.

The desired result of the method is to shrink fit a tool 18 into the tool holder 14, wherein the tool is to be positioned axially in the tool holder such that an overall length of the finished tool 18 and tool holder 14 assembly is a predetermined target length. The desired length is determined from the distance between a reference point on the tool side and a reference point on the tool holder side. In the exemplary embodiment, a front edge of a cutting edge, which can be easily detected optically by the detection arrangement 40, is used as the tool-side reference point R2.

The radial contact surface 38 of the tool holder 14, ie the end face of the tool holder 14 facing away from the tool 18, serves as the reference point R1 on the tool holder side. However, this area is mostly not designed for a precise calibration and/or a sufficiently accurate optical detection. For this reason, in the present exemplary embodiment of the method according to the invention, it is proposed to first dismantle the clamping device 34 from the frame element 30 and instead attach a calibration body 94 to the frame element 30 (cf Figure 2b ) to assemble. The calibration body 94 has mounting means 95 for mounting on the frame element and, in the assembled state, has the same axial length as the clamping device 34. However, a front edge or surface of the calibration body 94 facing away from the frame element 30 forms a very precise and optical Capture well suited edge or curve. For example, a sphere 96 can be considered here, the rounding of which can be optically sharply imaged in the axial zenith in relation to the background. This edge or rounding on the axial end of the calibration body 96 is then located exactly at the first reference point R1, i.e. at the same axial position as the contact surface 36 of the clamping device 34 or the radial contact surface 38 of the tool holder 14.

After the calibration body has been installed, the second holding device 16, in which no tool 18 has been inserted at this point in time, is moved along the linear guide 20 to the first holding device 12 until the detection arrangement 40 detects the first reference point R1. The axial position of the second holding device 16 is set precisely such that the first reference point R1 of the calibration body is, for example, just in a target area of the camera image of the camera 42 . In this position, a marking function is activated on the control panel 25 of the measuring arrangement, for example a zero position of the measuring arrangement is set. A zero button 27 on the control panel 25 can be pressed for this purpose.

The second holding device 16 can then be removed from the first holding device 12, the calibration body can be dismantled and the clamping device 34 and the tool holder 14 can be mounted instead.

The holding device 16 can then be moved along the linear guide 20 into a position in which the display on the control panel 25 of the measuring arrangement shows the desired distance between the first reference point R1 and the second reference point R2, i.e. the desired total length of the assembly of tool holder and tool. At this axial position, the stop 26 is finally brought into contact with the second holding device 16 and fixed, so that it is axially immobile. The second holding device 16 can then be further removed from the first holding device 12 until a sufficient distance has been established for the tool 18 to be able to be conveniently inserted into the holding means 66 . For this purpose, for example, the clamping arrangement 70 can be actuated so that the engagement elements 74l, 74r are at a sufficient distance from one another to enable the tool 18 to be inserted. The tool can be held comfortably at the end on the shank side so as not to touch the cutting edges. The tool 18 is preferably positioned in the axial direction in such a way that the clamping sections 76l, 76r grip the tool at an end of the shank section facing the cutting edges, i.e. approximately in a central region of the tool 18. The clamping arrangement 70 can then be used to close the holding means 66 are actuated so that the engaging elements 74l, 74r move towards one another and the tool 18 is clamped between the clamping sections 76l, 76r.

In a next method step, the carriage 50 is displaced in the axial direction relative to the base section 24 by actuating the adjustment device 56 in such a way that a section of the tool 18 serving as a second reference point R2, in particular a front edge of a cutting edge, reaches a target area of the detection arrangement 40. In particular, the axial position of the tool 18 can be set precisely such that the second reference point R2 on the tool side is located exactly in a target area superimposed on the camera image of the camera 42 . Once this setting has been made, a display on the control panel 25 of the measuring arrangement now shows exactly the distance between the first reference point R1 and the second reference point R2.

In a subsequent method step, the tool holder 14 is opened. In the preferred case of a shrinking device, a heating device 86 is provided for this purpose, which z. B. has an annular induction heater, the receiving opening 88 fitting coaxially the tool holder 14 can be placed. In the illustrated exemplary embodiment, the heating device 86 can be moved in the axial direction on a rail 90 and can be pivoted about the rail 90 in such a way that it can be pivoted selectively into an active position and an inactive position. In the active position, the opening 88 of the heating device 86 is coaxial with the main axis X. In the inactive position, the heating device 86 is pivoted away from the main axis X in the radial direction and thus frees up space for the calibration steps described above or for subsequent cooling steps.

After the tool holder 14 has been heated to the desired temperature, the second holding device 16 can be moved along the linear guide 20 to the first holding device 12 until the tool 18 enters the tool holder 14 on the shank side. The second holding device 16 is moved up to the fixed stop 26 on the first holding device 12 . The distance between the first reference point R1 and the second reference point R2 then corresponds exactly to the desired length of the tool assembly.

While the tool 18 penetrates into the tool holder 14, any slight differences between the axis of the tool 18 and the axis of the receiving opening of the tool holder 14 can be dynamically compensated for by the holding means 66 being able to move dynamically in the movement range of the spring arrangement 80, so that a excessive stress on the tool 18 can be avoided.

In a subsequent method step, the tool holder 14 is closed. In the case of a shrinking device, this takes place by cooling the tool holder 14. In principle, the heating device 86 could be switched off or removed for this purpose. In order to shorten the shrinking process time, however, it is preferable to additionally use a Cooling device (not shown) attached to the tool holder. Preferably, the cooling device can be used with liquid CO ₂ . In a particularly preferred embodiment, the heating device 86 can also be used directly for cooling, in that after the heating means, in particular the induction coil, have been switched off, a coolant such as liquid CO ₂ is fed directly through the heating device 86 and cools the tool holder 14 . For example, nozzles integrated into the induction coil can be provided, through which liquid CO ₂ is sprayed onto the tool holder 14 . Such a combined heating and cooling unit has the advantage that the hot tool holder 14 is always protected against unintentional contact by an operator and a work step of removing the heating device 86 and bringing up a cooling device can be saved. In addition, the cooling process can be initiated very quickly in this way and the process times can be further reduced. Alternatively, other cooling methods, e.g. B. conceivable air cooling or cooling by placing a water-cooled heat sink.

After the tool holder 14 has been closed, the holding means 66 are opened in order to release the tool 18 . In particular, the control body 72 can be controlled to move the engagement elements 74l, 74r away from each other. As a result, the tool assembly consisting of tool holder and tool is now fully assembled and has the desired overall length.

In subsequent quality assurance steps, if desired, various parameters of the assembled tool assembly, such as the overall length or the concentricity or the diameter of the tool, can be checked. For this purpose, in particular, the tool assembly can remain mounted on the clamping device 34 and the detection arrangement 40 can be moved again in the axial direction for detecting the first reference point R1 and/or the second reference point R2 Check the overall length of the tool.

In a further embodiment variant of the invention, the tensioning device can be rotatable and driven in rotation by hand or by a motor arrangement. The detection arrangement 40 can detect the rotating tool 18 in a contactless manner, in particular can detect an optical image of the rotating tool. In this way, a radial deflection of the tool can be detected and, in particular, tracked on the screen, so that the concentricity of the tool 18 can be checked.

The detection of a rotating tool 18 in the embodiment variant described also offers the possibility of checking the diameter of the tool. This can be particularly advantageous for drilling or milling tools, where the chip flutes and the often asymmetrically distributed cutting edges make it difficult to measure the effective diameter in a simple, non-rotating view of the tool. On the other hand, by rotating the tool and capturing the image of the tool by the capturing arrangement 40, in particular the camera 42, an effective diameter of the tool can be determined very precisely.

With reference to figure 8 a second embodiment of the invention will be described below. The second embodiment is a modification of the first embodiment and differs from the first embodiment only with regard to the configuration of the second arm of the detection arrangement, so that with regard to all other features reference is expressly made to the description of the first embodiment.

In the second exemplary embodiment, the second arm 48b of the detection device 40 is on a linear guide 100b in the axial direction movably mounted relative to the base portion 24 of the second holding device 16 . The movement is limited in a direction towards the first holding device by a stop 102b on the base section 24 against which the second arm 48b can stop. A cantilever spring assembly, not shown, biases the second arm 48b toward the stop 102b.

When the second arm 48b is in contact with the stop 102b of the base section 24, the optical axis L1 of the lighting device 44 held on the second arm lies on the optical axis L2 of the camera 42, so that the detection arrangement is ready for the detection of the tool and in particular the lighting device is positioned in the correct position for lighting the tool in the area of the second reference point. The cantilever spring arrangement reliably holds the second arm 48b on the stop 102b, so that when the second holding device 16 moves axially relative to the first holding device 12, the second arm 48b is also moved and the optical axes L1 and L2 remain aligned with one another.

When the second holding device 16 approaches the first holding device 12 more closely, the second arm 48b finally comes into contact with a section assigned to the first holding device 12 at some point shortly before or during the insertion of the tool into the tool holder. in the in figure 8 In the exemplary embodiment shown, the second arm 48b strikes the heating device 86, which at this time is attached to the tool holder and has opened it. The heater 86 stops and thus limits the axial movement of the second arm 48b. If the second holding device 16 is moved further from this point in the direction of the first holding device 12 in order to insert the tool into the tool holder up to the desired axial position, the arm 48b is lifted off the stop 102b against the force of the cantilever spring arrangement (position according to Fig figure 8 ). So, for example, in If the second embodiment uses a heating device with larger dimensions (such as a heating arrangement with an integrated cooling arrangement), the deflection of the arm 48b nevertheless allows the two holding devices to approach sufficiently closely.

The cantilever spring arrangement can also take on an advantageous function when removing the tool from the tool holder: For this purpose, the second holding device 16 is extended up to the in figure 8 Position shown moved up close to the first holding device 12, so that the second arm 48b is lifted against the force of the cantilever spring assembly from the stop 102b. The second holding device is then actuated in such a way that it holds the tool. As a result, the force of the cantilever spring arrangement now acts between the tool and the tool holder. As soon as the tool holder opens (for example after the tool holder has been heated in the case of a shrink device), the cantilever spring arrangement automatically pulls the tool out of the tool holder.

Claims (9)

1. Apparatus (10) for inserting a tool (18) into a tool holder (14), comprising

   a first holding device (12) which is designed to hold a tool holder (14),

   a second holding device (16) which is designed to hold a tool (18),

   a linear guide (20) by means of which the second holding device (16) is movable relative to the first holding device (12) in an axial direction extending along or parallel to a main axis (X) in order to move the tool (18) towards the tool holder (14) and introduce it into the tool holder (14),

   a detecting arrangement (40) which is movable in an axial direction and which is designed to contactlessly detect an axial position of a first reference point (R1) associated with the first holding device (12) and to contactlessly detect an axial position of a second reference point (R2) of a tool (18) held by the second holding device (16), and

   a measuring arrangement which measures an axial displacement travel of the detecting arrangement (40),

   characterized in that the detecting arrangement (40) is connected to the second holding device (16) and moves together with the latter in the axial direction on the linear guide (20).
2. Apparatus (10) according to Claim 1, characterized in that the second holding device (16) comprises a base portion (24) mounted axially movably on the linear guide (20) and a carriage (50) mounted axially movably on the base portion (24), wherein the carriage (50) has holding means (66) for holding a tool (18).
3. Apparatus (10) according to Claim 1 or Claim 2, characterized by a stop (26) which is displaceable in the axial direction and is able to be fixed respectively in different axial positions, wherein the stop is designed to limit an axial movement of the second holding device (16) along the linear guide (20).
4. Apparatus (10) according to one of the preceding claims, characterized in that the first holding device (12) comprises:

   a frame element (30),

   a clamping apparatus (34) which is able to be mounted on the frame element and has first coupling means for coupling a tool holder (14), and

   a calibration body which is able to be mounted on the frame element instead of the clamping apparatus,

   wherein the first reference point (R1) is provided at a contactlessly detectable edge or face of the calibration body, wherein preferably the axial length of the calibration body is equal to the axial length of the clamping apparatus (34) and wherein the first reference point (R1) is provided at an axial end, remote from the frame element, of the calibration body and is formed preferably by an edge or a rounding.
5. Apparatus (10) according to one of the preceding claims, characterized in that the tool (18) is a rotary tool, and in that the tool holder (14) is a tool chuck for holding the rotary tool.
6. Apparatus (10) according to one of the preceding claims, characterized

   in that the apparatus (10) is a shrinking apparatus,

   in that the apparatus comprises a heating device (86) for heating a tool holder held on the first holding device, and

   in that the apparatus preferably also comprises a cooling device for cooling the tool holder, wherein preferably,

   the cooling device for cooling the tool holder is integrated into the housing of the heating device (86), and/or

   the cooling device is designed to cool the tool holder (14) held on the first holding device (16) after heating by spraying on CO₂, wherein furthermore preferably,

   the cooling device has preferably three or more CO₂ outlet openings directed towards the tool holder (14).
7. Apparatus according to one of the preceding claims, characterized in that the second holding device (16) comprises:

   a base portion (24) mounted axially movable on the linear guide (20),

   an extension arm portion (48b) which is mounted axially movable with respect to the base portion (24) and preferably carries a component of the detecting arrangement (40), for example an illumination device (44),

   an extension arm spring arrangement which preloads the extension arm portion (48b) in the axial direction towards the base portion (24) and towards the first holding device,

   wherein the base portion (24) has a stop (102b) which limits the axial movement of the extension arm portion (48b).
8. Method for inserting a tool (18) into a tool holder (14), comprising the steps of

   a. providing the tool holder and tool at an axial distance from one another,

   b. contactlessly detecting the axial position of a first reference point (R1) associated with the tool holder,

   c. contactlessly detecting the axial position of a second reference point (R2) associated with the tool,

   d. opening the tool holder (14),

   e. introducing the tool (18) into the tool holder (14) such that a distance between the first reference point (R1) and the second reference point (R2) adopts a predetermined intended value,

   f. closing the tool holder (14).
9. Method according to Claim 8, characterized in that an apparatus (10) is used, which comprises:

   a first holding device (12) which is designed to hold a tool holder (14),

   a second holding device (16) which is designed to hold a tool (18),

   a linear guide (20) by means of which the second holding device is movable axially relative to the first holding device in order to move the tool towards the tool holder and introduce it into the tool holder,

   a detecting arrangement (40) which is axially movable and which is designed to contactlessly detect an axial position of a first reference point (R1) associated with the first holding device and to contactlessly detect an axial position of a second reference point (R2) of a tool held by the second holding device, and

   a measuring arrangement which measures an axial displacement travel of the detecting arrangement,

   wherein the apparatus (10) is preferably an apparatus according to one of Claim 1 to 7, and

   wherein the method comprises the following steps:

   g. contactlessly detecting the axial position of the first reference point (R1),

   h. axially moving the detecting device (40) by a predetermined axial displacement travel,

   i. setting a positioning device (26) in accordance with the axial position of the detecting device (40),

   j. inserting the tool (18) into the second holding device (16),

   k. contactlessly detecting the axial position of the second reference point (R2) of the tool (18) held by the second holding device (16),

   l. opening the tool holder (14),

   m. moving the second holding device (16) and the first holding device (12) towards one another such that the tool passes into the tool holder,

   n. stopping the moving-together movement by way of the positioning device (26),

   o. closing the tool holder (14),

   p. releasing the tool (18) from the second holding device (16).

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